Atomic structure and dynamics of epitaxial platinum bilayers on graphene

Platinum atomic layers grown on graphene were investigated by atomic resolution transmission electron microscopy (TEM). These TEM images reveal the epitaxial relationship between the atomically thin platinum layers and graphene, with two optimal epitaxies observed. The energetics of these epitaxies...

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主要な著者: Robertson, A, Lee, G, Lee, S, Buntin, P, Drexler, M, Abdelhafiz, A, Yoon, E, Warner, J, Alamgir, F
フォーマット: Journal article
言語:English
出版事項: American Chemical Society 2019
主題:
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author Robertson, A
Lee, G
Lee, S
Buntin, P
Drexler, M
Abdelhafiz, A
Yoon, E
Warner, J
Alamgir, F
author_facet Robertson, A
Lee, G
Lee, S
Buntin, P
Drexler, M
Abdelhafiz, A
Yoon, E
Warner, J
Alamgir, F
author_sort Robertson, A
collection OXFORD
description Platinum atomic layers grown on graphene were investigated by atomic resolution transmission electron microscopy (TEM). These TEM images reveal the epitaxial relationship between the atomically thin platinum layers and graphene, with two optimal epitaxies observed. The energetics of these epitaxies influences the grain structure of the platinum film, facilitating grain growth via in-plane rotation and assimilation of neighbor grains, rather than grain coarsening from the movement of grain boundaries. This growth process was enabled due to the availability of several possible low-energy intermediate states for the rotating grains, the Pt-Gr epitaxies, which are minima in surface energy, and coincident site lattice grain boundaries, which are minima in grain boundary energy. Density functional theory calculations reveal a complex interplay of considerations for minimizing the platinum grain energy, with free platinum edges also having an effect on the relative energetics. We thus find that the platinum atomic layer grains undergo significant reorientation to minimize interface energy (via epitaxy), grain boundary energy (via low-energy orientations), and free edge energy. These results will be important for the design of two-dimensional graphene-supported platinum catalysts and obtaining large-area uniform platinum atomic layer films and also provide fundamental experimental insight into the growth of heteroepitaxial thin films.
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spelling oxford-uuid:d52cfe6b-e22e-4cd6-8563-e992993c7ef32022-03-27T08:24:16ZAtomic structure and dynamics of epitaxial platinum bilayers on grapheneJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:d52cfe6b-e22e-4cd6-8563-e992993c7ef3Grain boundaries EpitaxyPlatinumGrainTwo dimensional materialsEnglishSymplectic Elements at OxfordAmerican Chemical Society2019Robertson, ALee, GLee, SBuntin, PDrexler, MAbdelhafiz, AYoon, EWarner, JAlamgir, FPlatinum atomic layers grown on graphene were investigated by atomic resolution transmission electron microscopy (TEM). These TEM images reveal the epitaxial relationship between the atomically thin platinum layers and graphene, with two optimal epitaxies observed. The energetics of these epitaxies influences the grain structure of the platinum film, facilitating grain growth via in-plane rotation and assimilation of neighbor grains, rather than grain coarsening from the movement of grain boundaries. This growth process was enabled due to the availability of several possible low-energy intermediate states for the rotating grains, the Pt-Gr epitaxies, which are minima in surface energy, and coincident site lattice grain boundaries, which are minima in grain boundary energy. Density functional theory calculations reveal a complex interplay of considerations for minimizing the platinum grain energy, with free platinum edges also having an effect on the relative energetics. We thus find that the platinum atomic layer grains undergo significant reorientation to minimize interface energy (via epitaxy), grain boundary energy (via low-energy orientations), and free edge energy. These results will be important for the design of two-dimensional graphene-supported platinum catalysts and obtaining large-area uniform platinum atomic layer films and also provide fundamental experimental insight into the growth of heteroepitaxial thin films.
spellingShingle Grain boundaries Epitaxy
Platinum
Grain
Two dimensional materials
Robertson, A
Lee, G
Lee, S
Buntin, P
Drexler, M
Abdelhafiz, A
Yoon, E
Warner, J
Alamgir, F
Atomic structure and dynamics of epitaxial platinum bilayers on graphene
title Atomic structure and dynamics of epitaxial platinum bilayers on graphene
title_full Atomic structure and dynamics of epitaxial platinum bilayers on graphene
title_fullStr Atomic structure and dynamics of epitaxial platinum bilayers on graphene
title_full_unstemmed Atomic structure and dynamics of epitaxial platinum bilayers on graphene
title_short Atomic structure and dynamics of epitaxial platinum bilayers on graphene
title_sort atomic structure and dynamics of epitaxial platinum bilayers on graphene
topic Grain boundaries Epitaxy
Platinum
Grain
Two dimensional materials
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